1. Field of the Invention
Embodiments of the invention generally relate to devices and methods used in vapor deposition, and more specifically relate to sputtering targets used in physical vapor deposition (PVD) and methods for forming the same.
2. Description of the Related Art
Nickel-based materials, including metallic nickel and nickel-platinum alloys, are often used in the manufacturing of electronic and semiconductor devices. Nickel-platinum alloys have gained popularity for use in silicide applications. Often, the nickel-platinum alloys, as well as other materials, are deposited from a sputtering target or PVD target during a radio-frequency (RF) PVD process. The sputtering target usually contains a nickel target adhered to a backing plate. The nickel target is typically of a high purity metal, such as 99.9% or greater, and may contain metallic nickel or a nickel alloy. The backing plate is usually composed of a highly conductive metal, such as a copper material.
The sputtering target is exposed to a plasma while being sputtered during a PVD process. Besides sputtering the metallic target material (e.g., nickel) during the process, other metallic material derived from exposed surfaces within the PVD chamber may also be removed or eroded during the PVD process. Such metallic material causes particulate contamination in the PVD chamber and therefore severely compromises the deposited materials on the substrate. Ceramic liners or shields are often used to cover and protect stainless steel and/or aluminum surfaces of the PVD chamber from the plasma. However, other metallic surfaces, such as exposed regions on target backing plates, are usually not protected by ceramic liners and shields and therefore are directly exposed to the plasma. Since many backing plates are composed of a copper material, highly conductive particles and contaminants are often generated and disembark on to surfaces within the PVD chamber or directly on to the substrate. The conductive contaminants eventually compromise the substrate fabrication process.
Therefore, there is a need to provide a sputtering target free or substantially free of a contaminant source when exposed to plasma during a sputtering or PVD process.